Containers



Sept. 9, 1969 figwg ETAL 3,465,947

CONTAINERS 2 Sheets-Sheet 1 Filed March 5, 1968 FIG].

8 W mu mA 8 m mw s N w as N w H TN Ml. mm H K K B 5 MORGAN, FINNEGAN.DURHAM a PlNE ATTORNEYS Sept. 9, 1969 K.E. ANDREWS ETAL 3,465,947

CONTAINERS Filed March 5, 1968 2 Sheets-Sheet 2 INVENTORS,

KEVIN WESTMAK BY MORGAN, FINNEGAN. DURHAM 8 PINE ATTORNEYS KENNETHERNEST ANDREWS United States Patent 3,465,947 CONTAINERS Kenneth ErnestAndrews and Kevin Westman, Gloucester, England, assignors to The BritishPetroleum Company Limited, London, England, a corporation of GreatBritain Filed Mar. 5, 1968, Ser. No. 710,573 Claims priority,application Great Britain, Mar. 8, 1967, 10,825 67 Int. Cl. B65d /64,3/24 US. Cl. 229-44 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates to containers, particularly although not exclusively, tocontainers for eggs.

For many years, eggs have been transported and sold in disposable eggboxes. These boxes are generally manufactured in moulded pulp andconsist of an integral unit comprising a base section, a lid section anda locking flap. The base section is often moulded to provide round orroughly semi-ovoidal depressions into which eggs can nest, thedepressions being separated by ribs which prevent eggs from contactingone another and also give strength to the base. The cover may be plainin construction or may be provided with identations and/ or cut outs ormay be similar to the base. Sometimes the sides and top of the coversection are contoured. The lid is hinged to the base and it is necessaryto provide a locking device which holds the lid firmly in position whenit is folded over onto the base, yet which may be released quickly andeasily when desired. The locking device is generally a flap hinged tothe base on the opposite side of the base from the lid and co-acting insome fashion with the lid when the latter is in the closed position.Many locking devices of this type have been proposed.

It is an object of the present invention to provide a containercomprising a new and improved locking device.

Thus according to the present invention there is provided a container ofthe type comprising a base section, a cover section and a locking flap,the cover section being hinged to the base section along at least partof one side, the locking fiap being hinged to the base section along atleast part of the opposite side, the locking flap containing at leastone recess or projection adapted to fit in locking relationship with atleast one corresponding projection or recess on the cover section whenthe cover section is in the closed position.

Preferably the locking flap is adapted to fit inside the cover sectionwhen the latter is in the closed position.

Preferably the recess is located in the flap and the projection in thecover section.

Preferably the projection is in the form of a wedge, the deepest sectionof the wedge being uppermost when the cover is closed and the containeris in its normal position.

The distance of protrusion of the wedge should equal or be slightly lessthan the depth of the recess.

Preferably the deepest section of the wedge and the 3,465,947 PatentedSept. 9, 1969 corresponding surface of the recess are set at such anglesto the side of the cover section and the side of the locking flaprespectively, that on closing the box, the deepest section of the wedgeforms a re-entrant with the corresponding surface of the recess.

The angles should preferably be such that the re-entrant is destroyed byslightly distorting the wall of the cover portion of the containeradjacent to the flap. Thus a closed container may be opened by a forwardand up ward movement of the front of the cover.

Preferably the level of each hinge is below the level of the uppersurfaces of the portions which are united through the hinge. Thisfeature confers resiliency on the hinges, thus holding the lockingdevice more firmly in position when the container is closed and tendingto release it more quickly when a slight force is applied to open thecontainer.

The height of the flap advantageously corresponds to or is slightly lessthan the height of the cover section, to add strength to the structure.

Again in the interests of strength the distance from the top of therecess to the internal surface of the top of the cover of the box shouldbe made as short as possible, whilst at the same time maintaining thestrength required at the top of the locking flap, and the requirednestability of the packs within each other.

Very suitable materials of construction for the containers are formed bythermoplastic resins, particularly formed thermoplastic resin, and moreespecially foamed polystyrene sheet and toughened polystyrene sheet.

Containers according to the present invention are suitable for use inthe storage of eggs, fruit and other fragile or soft commodities,amongst other applications.

The invention is illustrated by the accompanying drawings wherein FIGURE1 is a plan view of an open egg box according to the present invention.FIGURE 2 is an end elevation of the egg box of FIGURE 1, FIGURE 3 is asection of a portion of the egg box in the closed position and FIGURE 4is an isometric view of the egg box in a partially open position.

With reference to the figures, the egg box comprises a base portion 1, alid portion 2 and a locking flap 3. The base 1 is connected to the lid 2through a hinge 4 which is integral with both the base 1 and the lid 2.Similarly the flap 3 is connected to the base 1 through a hinge 5 whichis integral with the base 1 and the flap 3. The hinges 4 and 5 are belowthe levels of the upper surfaces of the base 1, lid 2 and flap 3.

The base 1 includes '6 egg cells 6 separated by relatively high ribs 7and low ribs 8 radiating from centres 10. The high ribs 7 provide formaximum egg separation but a structure in which all ribs are high wouldtend to flex too readily. The staggered low ribs 8 increase the rigidityof the structure. Intermediate ribs 9 are set at such a height thattheir bases form a guide for an appropriate element of a packingmachine.

The lid 2 comprises 4 inserts 11 which serve the double function ofpartially surrounding eggs, thereby increasing the protection which thebox affords them, and reinforcing the strength of the lid 2. The inserts11 extend for substantially the full height of the lid 2. Twowedgeshaped latches 12 are provided which co-operate with recesses 13 onthe locking flap 3. The distance of the base 14 of the latch 12 from thetop surface of the cover 2 is the minimum which could readily beachieved. The latches 12 do not extend throughout the full height of thelid 2.

The angles of the recess 13 and the latches 12 are such that when thebox is closed, as in FIGURE 3, a reentrant is formed, and when the frontof the cover 2 is pried forward, the re-entrant is destroyed.

The material of construction of the egg box is foamed polystyrene sheet.

What we claim is:

1. A container comprising a base section, a cover section and a lockingflap, the cover section being hinged to the base section along at leastpart of one side, the locking flap being hinged to the base sectionalong at least part of the opposite side, the locking flap containing atleast one re-entrant portion adapted to fit in locking relationship withat least one corresponding re-entrant portion on the cover section whenthe cover section is in the closed position.

2. A container as claimed in claim 1 wherein the locking flap is adaptedto fit inside the cover section when the latter is in the closedposition. a

3. A container as claimed in claim 1 wherein said reentrant portionsprovide a recess located in the flap and a projection in the coversection.

4. A container as claimed in claim 3 wherein the projection is in theform of a wedge, the deepest section of the wedge being uppermost whenthe cover is closed and the container is in its normal position.

5. A container as claimed in claim 4 wherein the deepest section of thewedge and the corresponding surface of the recess are set at such anglesto the side of the cover section and the side of the locking flaprespectively, that on closing the box, the deepest section of the wedgeforms a re-entrant with the corresponding surface of the recess.

6. A container as claimed in claim 5 wherein the angles are such thatthe re-entrant is destroyed by slightly distorting the wall of the coverportion of the container adjacent to the flap.

7. A container as claimed in claim 1 wherein the level of each hinge isbelow the level of the upper surfaces of the portions which are unitedthrough the hinge.

8. A container as claimed in claim 1 wherein the height of the flapsubstantially equals the height of the cover section.

9. A container as claimed in claim 1 wherein the container is made froma thermoplastic resin.

10. A container as claimed in claim 9 wherein the thermoplastic resin isa foamed thermoplastic resin, e.g, foamed polystyrene sheet or toughenedpolystyrene sheet.

References Cited UNITED STATES PATENTS DAVID M. BOCKENEK, PrimaryExaminer US. Cl. X.R. 2292.5, 45

